xref: /freebsd/usr.bin/last/last.c (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
1 /*
2  * Copyright (c) 1987, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1987, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static const char sccsid[] = "@(#)last.c	8.2 (Berkeley) 4/2/94";
42 #endif /* not lint */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 
49 #include <err.h>
50 #include <fcntl.h>
51 #include <langinfo.h>
52 #include <locale.h>
53 #include <paths.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <time.h>
59 #include <unistd.h>
60 #include <utmp.h>
61 #include <sys/queue.h>
62 
63 #define	NO	0				/* false/no */
64 #define	YES	1				/* true/yes */
65 #define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
66 
67 static struct utmp	buf[1024];		/* utmp read buffer */
68 
69 typedef struct arg {
70 	char	*name;				/* argument */
71 #define	HOST_TYPE	-2
72 #define	TTY_TYPE	-3
73 #define	USER_TYPE	-4
74 	int	type;				/* type of arg */
75 	struct arg	*next;			/* linked list pointer */
76 } ARG;
77 ARG	*arglist;				/* head of linked list */
78 
79 LIST_HEAD(ttylisthead, ttytab) ttylist;
80 
81 struct ttytab {
82 	time_t	logout;				/* log out time */
83 	char	tty[UT_LINESIZE + 1];		/* terminal name */
84 	LIST_ENTRY(ttytab) list;
85 };
86 
87 static const	char *crmsg;			/* cause of last reboot */
88 static long	currentout,			/* current logout value */
89 		maxrec;				/* records to display */
90 static const	char *file = _PATH_WTMP;		/* wtmp file */
91 static int	sflag = 0;			/* show delta in seconds */
92 static int	width = 5;			/* show seconds in delta */
93 static int	yflag;				/* show year */
94 static int      d_first;
95 static int	snapfound = 0;			/* found snapshot entry? */
96 static time_t	snaptime;			/* if != 0, we will only
97 						 * report users logged in
98 						 * at this snapshot time
99 						 */
100 
101 void	 addarg(int, char *);
102 time_t	 dateconv(char *);
103 void	 doentry(struct utmp *);
104 void	 hostconv(char *);
105 void	 onintr(int);
106 void	 printentry(struct utmp *, struct ttytab *);
107 char	*ttyconv(char *);
108 int	 want(struct utmp *);
109 void	 usage(void);
110 void	 wtmp(void);
111 
112 void
113 usage(void)
114 {
115 	(void)fprintf(stderr,
116 "usage: last [-#] [-y] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
117 "\t[-t tty] [-s|w] [user ...]\n");
118 	exit(1);
119 }
120 
121 int
122 main(int argc, char *argv[])
123 {
124 	int ch;
125 	char *p;
126 
127 	(void) setlocale(LC_TIME, "");
128 	d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
129 
130 	maxrec = -1;
131 	snaptime = 0;
132 	while ((ch = getopt(argc, argv, "0123456789d:f:h:st:wy")) != -1)
133 		switch (ch) {
134 		case '0': case '1': case '2': case '3': case '4':
135 		case '5': case '6': case '7': case '8': case '9':
136 			/*
137 			 * kludge: last was originally designed to take
138 			 * a number after a dash.
139 			 */
140 			if (maxrec == -1) {
141 				p = argv[optind - 1];
142 				if (p[0] == '-' && p[1] == ch && !p[2])
143 					maxrec = atol(++p);
144 				else
145 					maxrec = atol(argv[optind] + 1);
146 				if (!maxrec)
147 					exit(0);
148 			}
149 			break;
150 		case 'd':
151 			snaptime = dateconv(optarg);
152 			break;
153 		case 'f':
154 			file = optarg;
155 			break;
156 		case 'h':
157 			hostconv(optarg);
158 			addarg(HOST_TYPE, optarg);
159 			break;
160 		case 's':
161 			sflag++;	/* Show delta as seconds */
162 			break;
163 		case 't':
164 			addarg(TTY_TYPE, ttyconv(optarg));
165 			break;
166 		case 'w':
167 			width = 8;
168 			break;
169 		case 'y':
170 			yflag++;
171 			break;
172 		case '?':
173 		default:
174 			usage();
175 		}
176 
177 	if (sflag && width == 8) usage();
178 
179 	if (argc) {
180 		setlinebuf(stdout);
181 		for (argv += optind; *argv; ++argv) {
182 #define	COMPATIBILITY
183 #ifdef	COMPATIBILITY
184 			/* code to allow "last p5" to work */
185 			addarg(TTY_TYPE, ttyconv(*argv));
186 #endif
187 			addarg(USER_TYPE, *argv);
188 		}
189 	}
190 	wtmp();
191 	exit(0);
192 }
193 
194 /*
195  * wtmp --
196  *	read through the wtmp file
197  */
198 void
199 wtmp(void)
200 {
201 	struct utmp	*bp;			/* current structure */
202 	struct stat	stb;			/* stat of file for size */
203 	long	bl;
204 	int	bytes, wfd;
205 	char ct[80];
206 	struct tm *tm;
207 	time_t	t;
208 
209 	LIST_INIT(&ttylist);
210 
211 	if ((wfd = open(file, O_RDONLY, 0)) < 0 || fstat(wfd, &stb) == -1)
212 		err(1, "%s", file);
213 	bl = (stb.st_size + sizeof(buf) - 1) / sizeof(buf);
214 
215 	(void)time(&t);
216 	buf[0].ut_time = _time_to_int(t);
217 	(void)signal(SIGINT, onintr);
218 	(void)signal(SIGQUIT, onintr);
219 
220 	while (--bl >= 0) {
221 		if (lseek(wfd, (off_t)(bl * sizeof(buf)), L_SET) == -1 ||
222 		    (bytes = read(wfd, buf, sizeof(buf))) == -1)
223 			err(1, "%s", file);
224 		for (bp = &buf[bytes / sizeof(buf[0]) - 1]; bp >= buf; --bp)
225 			doentry(bp);
226 	}
227 	t = _int_to_time(buf[0].ut_time);
228 	tm = localtime(&t);
229 	(void) strftime(ct, sizeof(ct), "\nwtmp begins %+\n", tm);
230 	printf("%s", ct);
231 }
232 
233 /*
234  * doentry --
235  *	process a single wtmp entry
236  */
237 void
238 doentry(struct utmp *bp)
239 {
240 	struct ttytab	*tt, *ttx;		/* ttylist entry */
241 
242 	/*
243 	 * if the terminal line is '~', the machine stopped.
244 	 * see utmp(5) for more info.
245 	 */
246 	if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
247 		/* everybody just logged out */
248 		for (tt = LIST_FIRST(&ttylist); tt;) {
249 			LIST_REMOVE(tt, list);
250 			ttx = tt;
251 			tt = LIST_NEXT(tt, list);
252 			free(ttx);
253 		}
254 		currentout = -bp->ut_time;
255 		crmsg = strncmp(bp->ut_name, "shutdown", UT_NAMESIZE) ?
256 		    "crash" : "shutdown";
257 		/*
258 		 * if we're in snapshot mode, we want to exit if this
259 		 * shutdown/reboot appears while we we are tracking the
260 		 * active range
261 		 */
262 		if (snaptime && snapfound)
263 			exit(0);
264 		/*
265 		 * don't print shutdown/reboot entries unless flagged for
266 		 */
267 		if (!snaptime && want(bp))
268 			printentry(bp, NULL);
269 		return;
270 	}
271 	/*
272 	 * if the line is '{' or '|', date got set; see
273 	 * utmp(5) for more info.
274 	 */
275 	if ((bp->ut_line[0] == '{' || bp->ut_line[0] == '|') &&
276 	    !bp->ut_line[1]) {
277 		if (want(bp) && !snaptime)
278 			printentry(bp, NULL);
279 		return;
280 	}
281 	/* find associated tty */
282 	LIST_FOREACH(tt, &ttylist, list)
283 	    if (!strncmp(tt->tty, bp->ut_line, UT_LINESIZE))
284 		    break;
285 
286 	if (tt == NULL) {
287 		/* add new one */
288 		tt = malloc(sizeof(struct ttytab));
289 		if (tt == NULL)
290 			errx(1, "malloc failure");
291 		tt->logout = currentout;
292 		strncpy(tt->tty, bp->ut_line, UT_LINESIZE);
293 		LIST_INSERT_HEAD(&ttylist, tt, list);
294 	}
295 
296 	/*
297 	 * print record if not in snapshot mode and wanted
298 	 * or in snapshot mode and in snapshot range
299 	 */
300 	if (bp->ut_name[0] && (want(bp) || (bp->ut_time < snaptime &&
301 	    (tt->logout > snaptime || tt->logout < 1)))) {
302 		snapfound = 1;
303 		/*
304 		 * when uucp and ftp log in over a network, the entry in
305 		 * the utmp file is the name plus their process id.  See
306 		 * etc/ftpd.c and usr.bin/uucp/uucpd.c for more information.
307 		 */
308 		if (!strncmp(bp->ut_line, "ftp", sizeof("ftp") - 1))
309 			bp->ut_line[3] = '\0';
310 		else if (!strncmp(bp->ut_line, "uucp", sizeof("uucp") - 1))
311 			bp->ut_line[4] = '\0';
312 		printentry(bp, tt);
313 	}
314 	tt->logout = bp->ut_time;
315 }
316 
317 /*
318  * printentry --
319  *	output an entry
320  *
321  * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
322  * logout type (crash/shutdown) as appropriate.
323  */
324 void
325 printentry(struct utmp *bp, struct ttytab *tt)
326 {
327 	char ct[80];
328 	struct tm *tm;
329 	time_t	delta;				/* time difference */
330 	time_t	t;
331 
332 	if (maxrec != -1 && !maxrec--)
333 		exit(0);
334 	t = _int_to_time(bp->ut_time);
335 	tm = localtime(&t);
336 	(void) strftime(ct, sizeof(ct), d_first ?
337 	    (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
338 	    (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
339 	printf("%-*.*s %-*.*s %-*.*s %s%c",
340 	    UT_NAMESIZE, UT_NAMESIZE, bp->ut_name,
341 	    UT_LINESIZE, UT_LINESIZE, bp->ut_line,
342 	    UT_HOSTSIZE, UT_HOSTSIZE, bp->ut_host,
343 	    ct, tt == NULL ? '\n' : ' ');
344 	if (tt == NULL)
345 		return;
346 	if (!tt->logout) {
347 		puts("  still logged in");
348 		return;
349 	}
350 	if (tt->logout < 0) {
351 		tt->logout = -tt->logout;
352 		printf("- %s", crmsg);
353 	} else {
354 		tm = localtime(&tt->logout);
355 		(void) strftime(ct, sizeof(ct), "%R", tm);
356 		printf("- %s", ct);
357 	}
358 	delta = tt->logout - bp->ut_time;
359 	if (sflag) {
360 		printf("  (%8ld)\n", (long)delta);
361 	} else {
362 		tm = gmtime(&delta);
363 		(void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
364 		if (delta < 86400)
365 			printf("  (%s)\n", ct);
366 		else
367 			printf(" (%ld+%s)\n", (long)delta / 86400, ct);
368 	}
369 }
370 
371 /*
372  * want --
373  *	see if want this entry
374  */
375 int
376 want(struct utmp *bp)
377 {
378 	ARG *step;
379 
380 	if (snaptime)
381 		return (NO);
382 
383 	if (!arglist)
384 		return (YES);
385 
386 	for (step = arglist; step; step = step->next)
387 		switch(step->type) {
388 		case HOST_TYPE:
389 			if (!strncasecmp(step->name, bp->ut_host, UT_HOSTSIZE))
390 				return (YES);
391 			break;
392 		case TTY_TYPE:
393 			if (!strncmp(step->name, bp->ut_line, UT_LINESIZE))
394 				return (YES);
395 			break;
396 		case USER_TYPE:
397 			if (!strncmp(step->name, bp->ut_name, UT_NAMESIZE))
398 				return (YES);
399 			break;
400 		}
401 	return (NO);
402 }
403 
404 /*
405  * addarg --
406  *	add an entry to a linked list of arguments
407  */
408 void
409 addarg(int type, char *arg)
410 {
411 	ARG *cur;
412 
413 	if ((cur = malloc(sizeof(ARG))) == NULL)
414 		errx(1, "malloc failure");
415 	cur->next = arglist;
416 	cur->type = type;
417 	cur->name = arg;
418 	arglist = cur;
419 }
420 
421 /*
422  * hostconv --
423  *	convert the hostname to search pattern; if the supplied host name
424  *	has a domain attached that is the same as the current domain, rip
425  *	off the domain suffix since that's what login(1) does.
426  */
427 void
428 hostconv(char *arg)
429 {
430 	static int first = 1;
431 	static char *hostdot, name[MAXHOSTNAMELEN];
432 	char *argdot;
433 
434 	if (!(argdot = strchr(arg, '.')))
435 		return;
436 	if (first) {
437 		first = 0;
438 		if (gethostname(name, sizeof(name)))
439 			err(1, "gethostname");
440 		hostdot = strchr(name, '.');
441 	}
442 	if (hostdot && !strcasecmp(hostdot, argdot))
443 		*argdot = '\0';
444 }
445 
446 /*
447  * ttyconv --
448  *	convert tty to correct name.
449  */
450 char *
451 ttyconv(char *arg)
452 {
453 	char *mval;
454 
455 	/*
456 	 * kludge -- we assume that all tty's end with
457 	 * a two character suffix.
458 	 */
459 	if (strlen(arg) == 2) {
460 		/* either 6 for "ttyxx" or 8 for "console" */
461 		if ((mval = malloc(8)) == NULL)
462 			errx(1, "malloc failure");
463 		if (!strcmp(arg, "co"))
464 			(void)strcpy(mval, "console");
465 		else {
466 			(void)strcpy(mval, "tty");
467 			(void)strcpy(mval + 3, arg);
468 		}
469 		return (mval);
470 	}
471 	if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
472 		return (arg + 5);
473 	return (arg);
474 }
475 
476 /*
477  * dateconv --
478  * 	Convert the snapshot time in command line given in the format
479  * 	[[CC]YY]MMDDhhmm[.SS]] to a time_t.
480  * 	Derived from atime_arg1() in usr.bin/touch/touch.c
481  */
482 time_t
483 dateconv(char *arg)
484 {
485         time_t timet;
486         struct tm *t;
487         int yearset;
488         char *p;
489 
490         /* Start with the current time. */
491         if (time(&timet) < 0)
492                 err(1, "time");
493         if ((t = localtime(&timet)) == NULL)
494                 err(1, "localtime");
495 
496         /* [[CC]YY]MMDDhhmm[.SS] */
497         if ((p = strchr(arg, '.')) == NULL)
498                 t->tm_sec = 0; 		/* Seconds defaults to 0. */
499         else {
500                 if (strlen(p + 1) != 2)
501                         goto terr;
502                 *p++ = '\0';
503                 t->tm_sec = ATOI2(p);
504         }
505 
506         yearset = 0;
507         switch (strlen(arg)) {
508         case 12:                	/* CCYYMMDDhhmm */
509                 t->tm_year = ATOI2(arg);
510                 t->tm_year *= 100;
511                 yearset = 1;
512                 /* FALLTHOUGH */
513         case 10:                	/* YYMMDDhhmm */
514                 if (yearset) {
515                         yearset = ATOI2(arg);
516                         t->tm_year += yearset;
517                 } else {
518                         yearset = ATOI2(arg);
519                         if (yearset < 69)
520                                 t->tm_year = yearset + 2000;
521                         else
522                                 t->tm_year = yearset + 1900;
523                 }
524                 t->tm_year -= 1900;     /* Convert to UNIX time. */
525                 /* FALLTHROUGH */
526         case 8:				/* MMDDhhmm */
527                 t->tm_mon = ATOI2(arg);
528                 --t->tm_mon;    	/* Convert from 01-12 to 00-11 */
529                 t->tm_mday = ATOI2(arg);
530                 t->tm_hour = ATOI2(arg);
531                 t->tm_min = ATOI2(arg);
532                 break;
533         case 4:				/* hhmm */
534                 t->tm_hour = ATOI2(arg);
535                 t->tm_min = ATOI2(arg);
536                 break;
537         default:
538                 goto terr;
539         }
540         t->tm_isdst = -1;       	/* Figure out DST. */
541         timet = mktime(t);
542         if (timet == -1)
543 terr:           errx(1,
544         "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
545         return timet;
546 }
547 
548 
549 /*
550  * onintr --
551  *	on interrupt, we inform the user how far we've gotten
552  */
553 void
554 onintr(int signo)
555 {
556 	char ct[80];
557 	struct tm *tm;
558 	time_t t = _int_to_time(buf[0].ut_time);
559 
560 	tm = localtime(&t);
561 	(void) strftime(ct, sizeof(ct),
562 			d_first ? "%a %e %b %R" : "%a %b %e %R",
563 			tm);
564 	printf("\ninterrupted %s\n", ct);
565 	if (signo == SIGINT)
566 		exit(1);
567 	(void)fflush(stdout);			/* fix required for rsh */
568 }
569